Structural characterisation of high surface area reduced molybdenum oxide catalysts

Abstract

High surface area reduced molybdenum oxides have been prepared by the thermal decomposition and reduction of molybdenum (VI) oxalate. Nitrogen physisorption isotherms, analysed by the α_s-method, have been used to determine the physical structure of the oxides. The effect of temperature, water vapour pressure and the degree of reduction, on the physical structure of the oxides has been studied. It is found that reduction creates initially slit-shaped micropores, which on further reduction, or in the presence of water vapour, broaden into mesopores. The changes in structure which accompany the passivation or the annealing of reduced oxides are described.